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Ubeysinghe S, Kankanamge D, Thotamune W, Wijayaratna D, Mohan TM, Karunarathne A. Spatiotemporal Optical Control of Gαq-PLCβ Interactions. ACS Synth Biol 2024; 13:242-258. [PMID: 38092428 DOI: 10.1021/acssynbio.3c00490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2023]
Abstract
Cells experience time-varying and spatially heterogeneous chemokine signals in vivo, activating cell surface proteins including G protein-coupled receptors (GPCRs). The Gαq pathway activation by GPCRs is a major signaling axis with broad physiological and pathological significance. Compared with other Gα members, GαqGTP activates many crucial effectors, including PLCβ (Phospholipase Cβ) and Rho GEFs (Rho guanine nucleotide exchange factors). PLCβ regulates many key processes, such as hematopoiesis, synaptogenesis, and cell cycle, and is therefore implicated in terminal-debilitating diseases, including cancer, epilepsy, Huntington's Disease, and Alzheimer's Disease. However, due to a lack of genetic and pharmacological tools, examining how the dynamic regulation of PLCβ signaling controls cellular physiology has been difficult. Since activated PLCβ induces several abrupt cellular changes, including cell morphology, examining how the other pathways downstream of Gq-GPCRs contribute to the overall signaling has also been difficult. Here we show the engineering, validation, and application of a highly selective and efficient optogenetic inhibitor (Opto-dHTH) to completely disrupt GαqGTP-PLCβ interactions reversibly in user-defined cellular-subcellular regions on optical command. Using this newly gained PLCβ signaling control, our data indicate that the molecular competition between RhoGEFs and PLCβ for GαqGTP determines the potency of Gq-GPCR-governed directional cell migration.
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Affiliation(s)
- Sithurandi Ubeysinghe
- Department of Chemistry, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Dinesh Kankanamge
- Pain Center, Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Waruna Thotamune
- Department of Chemistry, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Dhanushan Wijayaratna
- Department of Chemistry, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Thomas M Mohan
- Department of Chemistry, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Ajith Karunarathne
- Department of Chemistry, Saint Louis University, St. Louis, Missouri 63103, United States
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Ubeysinghe S, Kankanamge D, Thotamune W, Wijayaratna D, Mohan TM, Karunarathne A. Spatiotemporal optical control of Gαq-PLCβ interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.10.552801. [PMID: 37609229 PMCID: PMC10441412 DOI: 10.1101/2023.08.10.552801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Cells experience time-varying and spatially heterogeneous chemokine signals in vivo, activating cell surface proteins, including G protein-coupled receptors (GPCRs). The Gαq pathway activation by GPCRs is a major signaling axis with a broad physiological and pathological significance. Compared to other Gα members, GαqGTP activates many crucial effectors, including PLCβ (Phospholipase Cβ) and Rho GEFs (Rho guanine nucleotide exchange factors). PLCβ regulates many key processes, such as hematopoiesis, synaptogenesis, and cell cycle, and is therefore implicated in terminal - debilitating diseases, including cancer, epilepsy, Huntington's Disease, and Alzheimer's Disease. However, due to a lack of genetic and pharmacological tools, examining how the dynamic regulation of PLCβ signaling controls cellular physiology has been difficult. Since activated PLCβ induces several abrupt cellular changes, including cell morphology, examining how the other pathways downstream of Gq-GPCRs contribute to the overall signaling has also been difficult. Here we show the engineering, validation, and application of a highly selective and efficient optogenetic inhibitor (Opto-dHTH) to completely disrupt GαqGTP-PLCβ interactions reversibly in user-defined cellular-subcellular regions on optical command. Using this newly gained PLCβ signaling control, our data indicate that the molecular competition between RhoGEFs and PLCβ for GαqGTP determines the potency of Gq-GPCR-governed directional cell migration.
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Kamato D, Gabr M, Kumarapperuma H, Chia ZJ, Zheng W, Xu S, Osman N, Little PJ. Gαq Is the Specific Mediator of PAR-1 Transactivation of Kinase Receptors in Vascular Smooth Muscle Cells. Int J Mol Sci 2022; 23:ijms232214425. [PMID: 36430902 PMCID: PMC9692893 DOI: 10.3390/ijms232214425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 11/22/2022] Open
Abstract
AIMS G protein-coupled receptor (GPCR) transactivation of kinase receptors greatly expands the actions attributable to GPCRs. Thrombin, via its cognate GPCR, protease-activated receptor (PAR)-1, transactivates tyrosine and serine/threonine kinase receptors, specifically the epidermal growth factor receptor and transforming growth factor-β receptor, respectively. PAR-1 transactivation-dependent signalling leads to the modification of lipid-binding proteoglycans involved in the retention of lipids and the development of atherosclerosis. The mechanisms of GPCR transactivation of kinase receptors are distinct. We aimed to investigate the role of proximal G proteins in transactivation-dependent signalling. MAIN METHODS Using pharmacological and molecular approaches, we studied the role of the G⍺ subunits, G⍺q and G⍺11, in the context of PAR-1 transactivation-dependent signalling leading to proteoglycan modifications. KEY FINDINGS Pan G⍺q subunit inhibitor UBO-QIC/FR900359 inhibited PAR-1 transactivation of kinase receptors and proteoglycans modification. The G⍺q/11 inhibitor YM254890 did not affect PAR-1 transactivation pathways. Molecular approaches revealed that of the two highly homogenous G⍺q members, G⍺q and G⍺11, only the G⍺q was involved in regulating PAR-1 mediated proteoglycan modification. Although G⍺q and G⍺11 share approximately 90% homology at the protein level, we show that the two isoforms exhibit different functional roles. SIGNIFICANCE Our findings may be extrapolated to other GPCRs involved in vascular pathology and highlight the need for novel pharmacological tools to assess the role of G proteins in GPCR signalling to expand the preeminent position of GPCRs in human therapeutics.
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Affiliation(s)
- Danielle Kamato
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia
- School of Environment and Science, Griffith University, Nathan, QLD 4111, Australia
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD 4102, Australia
- Correspondence:
| | - Mai Gabr
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Hirushi Kumarapperuma
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Zheng J. Chia
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Wenhua Zheng
- Centre of Reproduction, Development & Aging and Institute of Translation Medicine, Faculty of Health Sciences, University of Macau, Taipa, Macau 999078, China
| | - Suowen Xu
- Institute of Endocrine and Metabolic Diseases, The First Affiliated Hospital of University of Science and Technology of China, Hefei 230052, China
| | - Narin Osman
- School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083, Australia
| | - Peter J. Little
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD 4102, Australia
- Department of Pharmacy, Guangzhou Xinhua University, Guangzhou 510520, China
- Sunshine Coast Health Institute, University of the Sunshine Coast, Birtinya, QLD 4575, Australia
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Li J, Ge Y, Huang JX, Strømgaard K, Zhang X, Xiong XF. Heterotrimeric G Proteins as Therapeutic Targets in Drug Discovery. J Med Chem 2019; 63:5013-5030. [PMID: 31841625 DOI: 10.1021/acs.jmedchem.9b01452] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Heterotrimeric G proteins are molecular switches in GPCR signaling pathways and regulate a plethora of physiological and pathological processes. GPCRs are efficient drug targets, and more than 30% of the drugs in use target them. However, selectively targeting an individual GPCR may be undesirable in various multifactorial diseases in which multiple receptors are involved. In addition, abnormal activation or expression of G proteins is frequently associated with diseases. Furthermore, G proteins harboring mutations often result in malignant diseases. Thus, targeting G proteins instead of GPCRs might provide alternative approaches for combating these diseases. In this review, we discuss the biochemistry of heterotrimeric G proteins, describe the G protein-associated diseases, and summarize the currently known modulators that can regulate the activities of G proteins. The outlook for targeting G proteins to treat diverse diseases is also included in this manuscript.
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Affiliation(s)
- Jian Li
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, 510006 Guangzhou, Guangdong, P. R. China
| | - Yang Ge
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, 510006 Guangzhou, Guangdong, P. R. China
| | - Jun-Xiang Huang
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, 510006 Guangzhou, Guangdong, P. R. China
| | - Kristian Strømgaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Xiaolei Zhang
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, 510006 Guangzhou, Guangdong, P. R. China
| | - Xiao-Feng Xiong
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, 510006 Guangzhou, Guangdong, P. R. China
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5
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Zhang H, Nielsen AL, Strømgaard K. Recent achievements in developing selective Gqinhibitors. Med Res Rev 2019; 40:135-157. [DOI: 10.1002/med.21598] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/09/2019] [Accepted: 04/26/2019] [Indexed: 02/06/2023]
Affiliation(s)
- Hang Zhang
- Key Laboratory of Advanced Drug Preparation Technologies, Ministry of Education, Co‐innovation Center of Henan Province for New Drug R&D and Preclinical Safety, and School of Pharmaceutical SciencesZhengzhou UniversityZhengzhou Henan China
| | - Alexander L. Nielsen
- Department of Drug Design and Pharmacology, Center for BiopharmaceuticalsUniversity of CopenhagenCopenhagen Denmark
| | - Kristian Strømgaard
- Department of Drug Design and Pharmacology, Center for BiopharmaceuticalsUniversity of CopenhagenCopenhagen Denmark
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Govatati S, Pichavaram P, Janjanam J, Zhang B, Singh NK, Mani AM, Traylor JG, Orr AW, Rao GN. NFATc1-E2F1-LMCD1-Mediated IL-33 Expression by Thrombin Is Required for Injury-Induced Neointima Formation. Arterioscler Thromb Vasc Biol 2019; 39:1212-1226. [PMID: 31043075 PMCID: PMC6540998 DOI: 10.1161/atvbaha.119.312729] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Objective- IL (interleukin)-33 has been shown to play a role in endothelial dysfunction, but its role in atherosclerosis is controversial. Therefore, the purpose of this study is to examine its role in vascular wall remodeling following injury. Approach and Results- Thrombin induced IL-33 expression in a time-dependent manner in human aortic smooth muscle cells and inhibition of its activity by its neutralizing antibody suppressed thrombin induced human aortic smooth muscle cell migration but not DNA synthesis. In exploring the mechanisms, we found that Par1 (protease-activated receptor 1), Gαq/11 (Gα protein q/11), PLCβ3 (phospholipase Cβ3), NFATc1 (nuclear factor of activated T cells), E2F1 (E2F transcription factor 1), and LMCD1 (LIM and cysteine-rich domains protein 1) are involved in thrombin-induced IL-33 expression and migration. Furthermore, we identified an NFAT-binding site at -100 nt that mediates thrombin-induced IL-33 promoter activity. Interestingly, we observed that NFATc1, E2F1, and LMCD1 bind to NFAT site in response to thrombin and found that LMCD1, while alone has no significant effect, enhanced either NFATc1 or E2F1-dependent IL-33 promoter activity. In addition, we found that guidewire injury induces IL-33 expression in SMC and its neutralizing antibodies substantially reduce SMC migration and neointimal growth in vivo. Increased expression of IL-33 was also observed in human atherosclerotic lesions as compared to arteries without any lesions. Conclusions- The above findings reveal for the first time that thrombin-induced human aortic smooth muscle cell migration and injury-induced neointimal growth require IL-33 expression. In addition, thrombin-induced IL-33 expression requires LMCD1 enhanced combinatorial activation of NFATc1 and E2F1.
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MESH Headings
- Animals
- Binding Sites
- Cell Movement/drug effects
- Cell Proliferation/drug effects
- Co-Repressor Proteins/genetics
- Co-Repressor Proteins/metabolism
- Disease Models, Animal
- E2F1 Transcription Factor/genetics
- E2F1 Transcription Factor/metabolism
- Female
- Femoral Artery/drug effects
- Femoral Artery/injuries
- Femoral Artery/metabolism
- Femoral Artery/pathology
- HEK293 Cells
- Humans
- Interleukin-33/genetics
- Interleukin-33/metabolism
- LIM Domain Proteins/genetics
- LIM Domain Proteins/metabolism
- Male
- Mice, Inbred C57BL
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- NFATC Transcription Factors/genetics
- NFATC Transcription Factors/metabolism
- Neointima
- Promoter Regions, Genetic
- Signal Transduction
- Up-Regulation
- Vascular System Injuries/genetics
- Vascular System Injuries/metabolism
- Vascular System Injuries/pathology
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Affiliation(s)
- Suresh Govatati
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Prahalathan Pichavaram
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Jagadeesh Janjanam
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Baolin Zhang
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Nikhlesh K. Singh
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Arul M. Mani
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - James G. Traylor
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA
| | - A. Wayne Orr
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA
| | - Gadiparthi N. Rao
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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7
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Janjanam J, Zhang B, Mani AM, Singh NK, Traylor JG, Orr AW, Rao GN. LIM and cysteine-rich domains 1 is required for thrombin-induced smooth muscle cell proliferation and promotes atherogenesis. J Biol Chem 2018; 293:3088-3103. [PMID: 29326163 DOI: 10.1074/jbc.ra117.000866] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/09/2018] [Indexed: 11/06/2022] Open
Abstract
Restenosis arises after vascular injury and is characterized by arterial wall thickening and decreased arterial lumen space. Vascular injury induces the production of thrombin, which in addition to its role in blood clotting acts as a mitogenic and chemotactic factor. In exploring the molecular mechanisms underlying restenosis, here we identified LMCD1 (LIM and cysteine-rich domains 1) as a gene highly responsive to thrombin in human aortic smooth muscle cells (HASMCs). Of note, LMCD1 depletion inhibited proliferation of human but not murine vascular smooth muscle cells. We also found that by physically interacting with E2F transcription factor 1, LMCD1 mediates thrombin-induced expression of the CDC6 (cell division cycle 6) gene in the stimulation of HASMC proliferation. Thrombin-induced LMCD1 and CDC6 expression exhibited a requirement for protease-activated receptor 1-mediated Gαq/11-dependent activation of phospholipase C β3. Moreover, the expression of LMCD1 was highly induced in smooth muscle cells located at human atherosclerotic lesions and correlated with CDC6 expression and that of the proliferation marker Ki67. Furthermore, the LMCD1- and SMCαactin-positive cells had higher cholesterol levels in the atherosclerotic lesions. In conclusion, these findings indicate that by acting as a co-activator with E2F transcription factor 1 in CDC6 expression, LMCD1 stimulates HASMC proliferation and thereby promotes human atherogenesis, suggesting an involvement of LMCD1 in restenosis.
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Affiliation(s)
- Jagadeesh Janjanam
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163 and
| | - Baolin Zhang
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163 and
| | - Arul M Mani
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163 and
| | - Nikhlesh K Singh
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163 and
| | - James G Traylor
- the Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71103
| | - A Wayne Orr
- the Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71103
| | - Gadiparthi N Rao
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163 and
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8
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Kamato D, Mitra P, Davis F, Osman N, Chaplin R, Cabot PJ, Afroz R, Thomas W, Zheng W, Kaur H, Brimble M, Little PJ. Ga q proteins: molecular pharmacology and therapeutic potential. Cell Mol Life Sci 2017; 74:1379-1390. [PMID: 27815595 PMCID: PMC11107756 DOI: 10.1007/s00018-016-2405-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 10/19/2016] [Accepted: 10/31/2016] [Indexed: 12/15/2022]
Abstract
Seven transmembrane G protein-coupled receptors (GPCRs) have gained much interest in recent years as it is the largest class among cell surface receptors. G proteins lie in the heart of GPCRs signalling and therefore can be therapeutically targeted to overcome complexities in GPCR responses and signalling. G proteins are classified into four families (Gi, Gs, G12/13 and Gq); Gq is further subdivided into four classes. Among them Gαq and Gαq/11 isoforms are most crucial and ubiquitously expressed; these isoforms are almost 88% similar at their amino acid sequence but may exhibit functional divergences. However, uncertainties often arise about Gαq and Gαq/11 inhibitors, these G proteins might also have suitability to the invention of novel-specific inhibitors for each isoforms. YM-254890 and UBO-QIC are discovered as potent inhibitors of Gαq functions and also investigated in thrombin protease-activated receptor (PAR)-1 inhibitors and platelet aggregation inhibition. The most likely G protein involved in PAR-1 stimulates responses is one of the Gαq family isoforms. In this review, we highlight the molecular structures and pharmacological responses of Gαq family which may reflect the biochemical and molecular role of Gαq and Gαq/11. The advanced understanding of Gαq and Gαq/11 role in GPCR signalling may shed light on our understanding on cell biology, cellular physiology and pathophysiology and also lead to the development of novel therapeutic agents for a number of diseases.
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Affiliation(s)
- Danielle Kamato
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, 20 Cornwall Street, Woolloongabba, QLD, 4102, Australia
| | - Partha Mitra
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, 20 Cornwall Street, Woolloongabba, QLD, 4102, Australia
| | - Felicity Davis
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, 20 Cornwall Street, Woolloongabba, QLD, 4102, Australia
| | - Narin Osman
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, 20 Cornwall Street, Woolloongabba, QLD, 4102, Australia
- School of Medical Sciences, RMIT University, Bundoora, VIC, 3083, Australia
- Department of Immunology, Monash University, Melbounre, VIC, 3004, Australia
| | - Rebecca Chaplin
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, 20 Cornwall Street, Woolloongabba, QLD, 4102, Australia
| | - Peter J Cabot
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, 20 Cornwall Street, Woolloongabba, QLD, 4102, Australia
| | - Rizwana Afroz
- Department of Biochemistry, Primeasia University, Banani, 1213, Bangladesh
| | - Walter Thomas
- School of Biomedical Sciences, The University of Queensland, St. Lucia, QLD, 4102, Australia
| | - Wenhua Zheng
- Faculty of Health Sciences, University of Macau, Taipa, Macau, China
| | - Harveen Kaur
- Department of Chemistry, School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Margaret Brimble
- Department of Chemistry, School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Peter J Little
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, 20 Cornwall Street, Woolloongabba, QLD, 4102, Australia.
- School of Medical Sciences, RMIT University, Bundoora, VIC, 3083, Australia.
- Xinhua College of Sun Yat-sen University, Tianhe District, Guangzhou, 510520, China.
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Kamato D, Thach L, Bernard R, Chan V, Zheng W, Kaur H, Brimble M, Osman N, Little PJ. Structure, Function, Pharmacology, and Therapeutic Potential of the G Protein, Gα/q,11. Front Cardiovasc Med 2015; 2:14. [PMID: 26664886 PMCID: PMC4671355 DOI: 10.3389/fcvm.2015.00014] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/11/2015] [Indexed: 11/19/2022] Open
Abstract
G protein coupled receptors (GPCRs) are one of the major classes of cell surface receptors and are associated with a group of G proteins consisting of three subunits termed alpha, beta, and gamma. G proteins are classified into four families according to their α subunit; Gαi, Gαs, Gα12/13, and Gαq. There are several downstream pathways of Gαq of which the best known is upon activation via guanosine triphosphate (GTP), Gαq activates phospholipase Cβ, hydrolyzing phosphatidylinositol 4,5-biphosphate into diacylglycerol and inositol triphosphate and activating protein kinase C and increasing calcium efflux from the endoplasmic reticulum. Although G proteins, in particular, the Gαq/11 are central elements in GPCR signaling, their actual roles have not yet been thoroughly investigated. The lack of research of the role on Gαq/11 in cell biology is partially due to the obscure nature of the available pharmacological agents. YM-254890 is the most useful Gαq-selective inhibitor with antiplatelet, antithrombotic, and thrombolytic effects. YM-254890 inhibits Gαq signaling pathways by preventing the exchange of guanosine diphosphate for GTP. UBO-QIC is a structurally similar compound to YM-254890, which can inhibit platelet aggregation and cause vasorelaxation in rats. Many agents are available for the study of signaling downstream of Gαq/11. The role of G proteins could potentially represent a novel therapeutic target. This review will explore the range of pharmacological and molecular tools available for the study of the role of Gαq/11 in GPCR signaling.
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Affiliation(s)
- Danielle Kamato
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Lyna Thach
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Rebekah Bernard
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Vincent Chan
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Wenhua Zheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre , Guangzhou , China ; Faculty of Health Sciences, University of Macau , Macau , China
| | - Harveen Kaur
- Department of Chemistry, University of Auckland , Auckland , New Zealand
| | - Margaret Brimble
- Department of Chemistry, University of Auckland , Auckland , New Zealand
| | - Narin Osman
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Peter J Little
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
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10
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Abstract
Phospholipase C (PLC) enzymes convert phosphatidylinositol-4,5-bisphosphate into the second messengers diacylglycerol and inositol-1,4,5-triphosphate. The production of these molecules promotes the release of intracellular calcium and activation of protein kinase C, which results in profound cellular changes. The PLCβ subfamily is of particular interest given its prominent role in cardiovascular and neuronal signaling and its regulation by G protein-coupled receptors, as PLCβ is the canonical downstream target of the heterotrimeric G protein Gαq. However, this is not the only mechanism regulating PLCβ activity. Extensive structural and biochemical evidence has revealed regulatory roles for autoinhibitory elements within PLCβ, Gβγ, small molecular weight G proteins, and the lipid membrane itself. Such complex regulation highlights the central role that this enzyme plays in cell signaling. A better understanding of the molecular mechanisms underlying the control of its activity will greatly facilitate the search for selective small molecule modulators of PLCβ.
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Affiliation(s)
- Angeline M Lyon
- Life Sciences Institute and the Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan
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11
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Cvetkovic D, Dragan M, Leith SJ, Mir ZM, Leong HS, Pampillo M, Lewis JD, Babwah AV, Bhattacharya M. KISS1R induces invasiveness of estrogen receptor-negative human mammary epithelial and breast cancer cells. Endocrinology 2013; 154:1999-2014. [PMID: 23525242 DOI: 10.1210/en.2012-2164] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Kisspeptins (KPs), peptide products of the KISS1 metastasis-suppressor gene, are endogenous ligands for a G protein-coupled receptor (KISS1R). KISS1 acts as a metastasis suppressor in numerous human cancers. However, recent studies have demonstrated that an increase in KISS1 and KISS1R expression in patient breast tumors correlates with higher tumor grade and metastatic potential. We have shown that KP-10 stimulates invasion of estrogen receptor α (ERα)-negative MDA-MB-231 breast cancer cells via transactivation of the epidermal growth factor receptor (EGFR). Here, we report that either KP-10 treatment of ERα-negative nonmalignant mammary epithelial MCF10A cells or expression of KISS1R in MCF10A cells induced a mesenchymal phenotype and stimulated invasiveness. Similarly, exogenous expression of KISS1R in ERα-negative SKBR3 breast cancer cells was sufficient to trigger invasion and induced extravasation in vivo. In contrast, KP-10 failed to transactivate EGFR or stimulate invasiveness in the ERα-positive MCF7 and T47D breast cancer cells. This suggested that ERα negatively regulates KISS1R-dependent breast cancer cell migration, invasion, and EGFR transactivation. In support of this, we found that these KP-10-induced effects were ablated upon exogenous expression of ERα in the MDA-MB-231 cells, by down-regulating KISS1R expression. Lastly, we have identified IQGAP1, an actin cytoskeletal binding protein as a novel binding partner of KISS1R, and have shown that KISS1R regulates EGFR transactivation in breast cancer cells in an IQGAP1-dependent manner. Overall, our data strongly suggest that the ERα status of mammary cells dictates whether KISS1R may be a novel clinical target for treating breast cancer metastasis.
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Affiliation(s)
- Donna Cvetkovic
- Department of Physiology, The University of Western Ontario, London, Ontario, Canada, N6A 5C1
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Gαq G proteins modulate MMP-9 gelatinase during remodeling of the murine femoral artery. J Surg Res 2012; 181:32-40. [PMID: 22595017 DOI: 10.1016/j.jss.2012.04.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 04/04/2012] [Accepted: 04/17/2012] [Indexed: 11/24/2022]
Abstract
BACKGROUND Vessels heal after injury and G protein-coupled receptors are involved in the vascular smooth muscle cell proliferation required to form intimal hyperplasia. We have previously identified the role of Gαq in vascular smooth muscle cell proliferation in vitro. This study now examines the role of Gαq in the developing intimal hyperplasia in a murine model and the impact of disruption of Gαq signaling on intimal hyperplasia development. METHODS We employed a murine femoral wire injury model in which a micro-wire is passed through a branch of the femoral artery and used to denude the common femoral artery. We perfusion-fixed specimens and stained sections with hematoxylin-eosin and Movat's stains such that morphometric analysis could be performed using an Image-Pro system. We also harvested additional specimens of femoral artery and snap-froze them for Western blotting or zymography, to allow for the study of G protein expression and both protease expression and activity. We used contralateral vessels as controls. We immersed additional vessels in pluronic gel containing the chemical Gαq G protein inhibitors GP-2A, siRNA to Gαq or adenovirus containing mutant inactive Gαq. RESULTS Gαq expression increased in a time-dependent manner after femoral artery injury. Sham-operated vessels did not produce such a response. Inhibition of Gαq reduced cell proliferation without affecting cell migration. Interruption of Gαq signaling also inhibited the development of intimal hyperplasia. Inhibition of Gαq did not alter peak urinary-type plasminogen activator activity and expression, but did increase early plasminogen activator inhibitor-1 activity and expression. Inhibition of Gαq reduced peak metalloproteinase (MMP)-9 activity at Day 3 but did not influence peak MMP-2 activity at Day 7. Protein expression for MMP-9 was also decreased, but that of MMP-2 was not affected. There were no changes in the expression or the activity of the respective inhibitors for MMP-9 and MMP-2, and tissue inhibitor of metalloproteinases-1 and -2. CONCLUSIONS These data demonstrate that femoral wire injury in the mouse is associated with a time-dependent increase in Gαq expression. Inhibition of Gαq alters cell proliferation and is associated with decreased MMP-9 expression and activity.
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O'Sullivan JF, Martin K, Caplice NM. Microribonucleic acids for prevention of plaque rupture and in-stent restenosis: "a finger in the dam". J Am Coll Cardiol 2011; 57:383-9. [PMID: 21251577 DOI: 10.1016/j.jacc.2010.09.029] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2010] [Revised: 07/26/2010] [Accepted: 09/21/2010] [Indexed: 01/09/2023]
Abstract
Vascular smooth muscle cells (VSMCs), which make up the arterial medial layer, possess a phenotype switching capability. This modulation of VSMCs is important in the development of atherosclerotic vascular disease. It has been recognized that VSMCs may also have a stabilizing role in advanced atherosclerotic plaques. Moreover, reduction of the proliferative capacity of these cells may be of benefit in reducing neointimal hyperplasia following therapeutic percutaneous intervention. The biology of microribonucleic acids (miRNAs) and their ability to modify smooth muscle biology has recently emerged in a number of investigations. These studies elucidated the key role of miRNAs, miR-143 and miR-145, in particular, in the regulation of SMC homeostasis in vitro, in murine models of targeted gene deletion, and also in human vascular pathology. This review places this burgeoning knowledge within the wider context of atherosclerosis and restenosis and explores the therapeutic potential of miRNAs to change the fate of VSMCs within the plaque.
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Affiliation(s)
- John F O'Sullivan
- Centre for Research in Vascular Biology, Biosciences Institute, University College Cork, Cork, Ireland
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Singh S, Robinson M, Ismail I, Saha M, Auer H, Kornacker K, Robinson ML, Bates CM, McHugh KM. Transcriptional profiling of the megabladder mouse: a unique model of bladder dysmorphogenesis. Dev Dyn 2008; 237:170-86. [PMID: 18069694 DOI: 10.1002/dvdy.21391] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Recent studies in our lab identified a mutant mouse model of obstructive nephropathy designated mgb for megabladder. Homozygotic mgb mice (mgb-/-) develop lower urinary tract obstruction in utero due to a lack of bladder smooth muscle differentiation. This defect is the result of a random transgene insertion/translocation into chromosomes 11 and 16. Transcriptional profiling identified a significantly over-expressed cluster of gene products located on the translocated fragment of chromosome 16 including urotensin II-related peptide (Urp), which was shown to be preferentially over-expressed in developing mgb-/- bladders. Pathway analysis of mgb microarray data indicated dysregulation of at least 60 gene products associated with smooth muscle development. In conclusion, the results of this study indicate that the molecular pathways controlling normal smooth muscle development are severely altered in mgb-/- bladders, and provide the first evidence that Urp may play a critical role in bladder smooth muscle development.
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Affiliation(s)
- Sunita Singh
- Center for Cell and Developmental Biology, Columbus Children's Research Institute, Columbus, Ohio 43205, USA
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Roztocil E, Nicholl SM, Davies MG. Sphingosine-1-phosphate-induced oxygen free radical generation in smooth muscle cell migration requires Galpha12/13 protein-mediated phospholipase C activation. J Vasc Surg 2008; 46:1253-1259. [PMID: 18155002 DOI: 10.1016/j.jvs.2007.08.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Revised: 07/28/2007] [Accepted: 08/05/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND Sphingosine-1-phosphate (S-1-P) is a bioactive sphingolipid that stimulates the migration of vascular smooth muscle cell (VSMC) through G-protein coupled receptors; it has been shown to activate reduced nicotinamide dinucleotide phosphate hydrogen (NAD[P]H) oxidase. The role of phospholipase C (PLC) in oxygen free radical generation, and the regulation of VSMC migration in response to S-1-P, are poorly understood. METHODS Rat arterial VSMC were cultured in vitro. Oxygen free radical generation was measured by fluorescent redox indicator assays in response to S-1-P (0.1microM) in the presence and absence of the active PLC inhibitor (U73122; U7, 10nM) or its inactive analog U73343 (InactiveU7, 10nM). Activation of PLC was assessed by immunoprecipitation and Western blotting for the phosphorylated isozymes (beta and gamma). Small interfering (si) RNA to the G-proteins Galphai, Galphaq, and Galpha12/13 was used to downregulate specific proteins. Statistics were by one-way analysis of variance (n = 6). RESULTS S-1-P induced time-dependent activation of PLC-beta and PLC-gamma; PLC-beta but not PLC-gamma activation was blocked by U7 but not by InactiveU7. PLC-beta activation was Galphai-independent (not blocked by pertussis toxin, a Galphai inhibitor, or Galphai2 and Galphai3 siRNA) and Galphaq-independent (not blocked by glycoprotein [GP] 2A, a Galphaq inhibitor, or Galphaq siRNA). PLC-beta activation and cell migration was blocked by siRNA to Galpha12/13. Oxygen free radical generation induced by S-1-P, as measured by dihydroethidium staining, was significantly inhibited by U7 but not by InactiveU7. Inhibition of oxygen free radicals with the inhibitor diphenyleneiodonium resulted in decreased cell migration to S-1-P. VSMC mitogen-activated protein kinase activation and VSMC migration in response to S-1-P was inhibited by PLC- inhibition. CONCLUSION S-1-P induces oxygen free radical generation through a Galpha12/13, PLC-beta-mediated mechanism that facilitates VSMC migration. To our knowledge, this is the first description of PLC-mediated oxygen free radical generation as a mediator of S-1-P VSMC migration and illustrates the need for the definition of cell signaling to allow targeted strategies in molecular therapeutics for restenosis.
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Affiliation(s)
- Eliza Roztocil
- Vascular Biology and Therapeutics Program, Department of Surgery, University of Rochester, Rochester, NY 14642, USA
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Wang X, Adams LD, Pabón LM, Mahoney WM, Beaudry D, Gunaje J, Geary RL, Deblois D, Schwartz SM. RGS5, RGS4, and RGS2 expression and aortic contractibility are dynamically co-regulated during aortic banding-induced hypertrophy. J Mol Cell Cardiol 2007; 44:539-50. [PMID: 18207159 DOI: 10.1016/j.yjmcc.2007.11.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Revised: 10/04/2007] [Accepted: 11/29/2007] [Indexed: 11/26/2022]
Abstract
Overexpression of regulator of G protein signaling 5 (RGS5) in arteries over veins is the most striking difference observed using microarray analysis. The obvious question is what arterial function might require RGS5. Based on functions of homologous proteins in regulating cardiac mass and G-protein-coupled receptor (GPCR) signaling, we proposed that RGS5 and vascular expressed RGS2 and RGS4 could participate in regulating arterial hypertrophy. We used the suprarenal abdominal aorta banding model to induce hypertension and hypertrophy. All 3 RGS messages were expressed in unmanipulated aorta with RGS5 predominating. After 2 days, thoracic aorta lost expression of RGS5, 4, and 2. At 1 week, all three returned to normal, and at 28 days, they increased many fold above normal. Valsartan blockade of angiotensin II (angII)/angII type 1 receptor signaling prevented upregulation of RGS messages but only delayed mass increases, implying wall mass regulation involves both angII-dependent and angII-independent pathways. The abdominal aorta showed less dramatic expression changes in RGS5 and 4, but not 2. Again, those changes were delayed by valsartan treatment with no mass changes. Thoracic aorta contraction to GPCR agonists was examined in aortic explant rings to identify vessel wall physiological changes. In 2-day aorta, the response to Galphaq/i agonists increased above normal, while 28-day aorta had attenuated induced contraction via Galphaq/i agonist, implicating a connection between RGS message levels and changes in GPCR-induced contraction. In vitro overexpression studies showed RGS5 inhibits angII-induced signaling in smooth muscle cells. This study is the first experimental evidence that changes in RGS expression and function correlate with vascular remodeling.
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Affiliation(s)
- Xi Wang
- University of Washington, Department of Pathology, Seattle, Washington 98109, USA
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